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Dialing Scales
Dialing scales are used to lay out the face of a sundial geometrically. They were proposed by Samuel Foster in 1638, and produced by George Serle and Anthony Thompson in 1658 on a ruler. There are two scales: the latitude scale and the hour scale. They can be used to draw all gnomonic dials – and reverse engineer existing dials to discover their original intended location. History Dialing scales were first discussed by Samuel Foster in 1638. P. Pierre Bobynet, a Jesuit drew a scale in his book ''L'horographie ingenieuse contenant des Connoissances, & Curiositez Agréables dans la composition des Cadrans'', in 1647. It was however George Serles 1657 book, ''Dialling Universal'', printed by R & W Leybourn that brought them to popular attention. These scales remained virtually unchanged for 250 years. E. C. Middleton, who had been engraving dialling scales from about 1895, supplied dialling scales accompanied by a typewritten instruction book from Birmingham in 1913– these wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sundial
A sundial is a horological device that tells the time of day (referred to as civil time in modern usage) when direct sunlight shines by the apparent position of the Sun in the sky. In the narrowest sense of the word, it consists of a flat plate (the ''dial'') and a gnomon, which casts a shadow onto the dial. As the Sun appears to move through the sky, the shadow aligns with different hour-lines, which are marked on the dial to indicate the time of day. The ''style'' is the time-telling edge of the gnomon, though a single point or ''nodus'' may be used. The gnomon casts a broad shadow; the shadow of the style shows the time. The gnomon may be a rod, wire, or elaborately decorated metal casting. The style must be parallel to the axis of the Earth's rotation for the sundial to be accurate throughout the year. The style's angle from horizontal is equal to the sundial's geographical latitude. The term ''sundial'' can refer to any device that uses the Sun's altitude or azimut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samuel Foster
Samuel Foster ( 1600 – July 1652) was an English mathematician and astronomer. He made several observations of eclipses, both of the sun and moon, at Gresham College and in other places; and he was known particularly for inventing and improving planetary instruments. Life A native of Northamptonshire, he was admitted a sizar at Emmanuel College, Cambridge on 23 April 1616, as a member of which he proceeded B.A. in 1619, and M.A. in 1623. On the death of Henry Gellibrand, he was elected Gresham Professor of Astronomy on 2 March 1636, but resigned later in the year and was succeeded by Mungo Murray. In 1641, Murray having vacated the professorship by his marriage, Foster was re-elected on 26 May. During the civil war and Commonwealth he was one of the society of gentlemen who met in London for cultivating the 'new philosophy,' in the group around Charles Scarburgh. In 1646 John Wallis received from Foster a theorem on spherical triangles (two antipodal triangles, that is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Serle
George may refer to: People * George (given name) * George (surname) * George (singer), American-Canadian singer George Nozuka, known by the mononym George * George Washington, First President of the United States * George W. Bush, 43rd President of the United States * George H. W. Bush, 41st President of the United States * George V, King of Great Britain, Ireland, the British Dominions and Emperor of India from 1910-1936 * George VI, King of Great Britain, Ireland, the British Dominions and Emperor of India from 1936-1952 * Prince George of Wales * George Papagheorghe also known as Jorge / GEØRGE * George, stage name of Giorgio Moroder * George Harrison, an English musician and singer-songwriter Places South Africa * George, Western Cape ** George Airport United States * George, Iowa * George, Missouri * George, Washington * George County, Mississippi * George Air Force Base, a former U.S. Air Force base located in California Characters * George (Peppa Pig), a 2-year-old ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
